1.0 INTRODUCTION 



The quality of sediments is critical to the ecological health of 

 aquatic ecosystems. Benthic organisms that live in sediments are key 

 links in food chains that lead from nutrients in water and sediment to 

 higher level consumers, such as fish and ducks. Sediments in aquatic 

 systems can be both sinks and sources for inorganic and organic contami- 

 nants. At present,. the extent of the sediment contamination problem is 

 largely unknown. Comprehensive assessments of the accumulation of 

 contaminants from agricultural, municipal, and industrial sources in 

 sediments of our rivers, lakes and estuaries have not been completed. 

 Currently, the U.S. Environmental Protection Agency has identified 134 

 sites with serious sediment contamination problems (USEPA 1988). In 

 addition, 41 areas in the Great Lakes (IJC 1988), 50 coastal sites, and 

 85 wildlife refuges have been identified where contaminated sediments 

 pose a problem (USEPA 1988). 



In Illinois, contaminants have been identified in sediments 

 throughout much of the Illinois River and its associated tributaries and 

 waterways (Figures 1.1 and 1.2; Cahill and Steele 1986; Cahill and 

 Autrey 1987; Blodgett et al . 1984; Mathis et al . 1973; Polls et al . 

 1985; Harrison et al . 1981; Coleman and Sanzolone 1991; Bhowmik and 

 Demissie 1989; Sparks and Blodgett 1984; and Fitzpatrick and Bhowmik 

 1990). Two-thirds of the population of the state lives in the Illinois 

 River basin which drains approximately half the state (Talkington 1991). 

 The river historically has been one of the most productive rivers in 

 North America in terms of fish and wildlife populations. In 1908, 



